It also detects if you are right or wrong

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

If you are trying to move an attached term across the equal sign (=), what operation would you use to move it?

What expression is equivalent to log3(x+4)